单项选择题
An occulting light is one in which （）.
A.the period of darkness exceeds the period of light B.there is only a partial eclipse of the light C.the periods of light and darkness are equal D.the period of light exceeds the period of darkness
单项选择题 AFTER DROPPING THE PILOT means （）.
单项选择题 Above-normal tides near the center of a hurricane maybe caused by the （）.
单项选择题 A vessel not to impede the passage of another vessel is not relieved （） taking collision-avoiding action.
